header {
    width: 97%;
    height: 20px;
    text-align: center;
    position: fixed;
    top: 46px;
    left: 50px;
    -moz-transition: all 0.5s ease;
    -o-transition: all 0.5s ease;
    -webkit-transition: all 0.5s ease;
    transition: all 0.5s ease;
    z-index: 99;
    opacity: 0.5;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    background-image: -webkit-linear-gradient(top,#f5f5f5,#eee);
    font-size: 15px;
}

header:hover{
    opacity: 1;
    height: 50px;
}

header nav {
    position: absolute;
    bottom: 0;
    height: 60px;
    line-height: 10px;
    width: 100%;
}

header nav .menu-header{
    margin-top: 18px;
}

header nav a {
    color: black;
    display: inline-block;
    padding: 10px 15px;
    line-height: 1;
    text-decoration: none;
    -moz-border-radius: 2px;
    -webkit-border-radius: 2px;
    border-radius: 2px;
}

header nav a:hover {
    -moz-box-shadow: 0 0 0 1px #fff;
    -webkit-box-shadow: 0 0 0 1px #fff;
    box-shadow: 0 0 0 1px #fff;
    text-decoration: none;
    color: #34A0CE;
}

header nav .dropdown {
    position: relative;
    display: inline-block;
}

header nav .dropdown:hover>.dropdown-content {
    display: block;
}

header nav .dropdown-content {
    display: none;
    position: absolute;
    background-color: white;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    padding: 8px 12px;
}

header nav .dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}

header nav .dropdown-content a:hover{
    -moz-box-shadow: 0 0 0 1px #fff;
    -webkit-box-shadow: 0 0 0 1px #fff;
    box-shadow: 0 0 0 1px #fff;
    text-decoration: none;
    color: #34A0CE;
}